Welder



FIG. 1 is a perspective view of a welder embodying the ornamental design of the present invention;

FIG. 2 is a side view of the welder, the opposite side view being a mirror image;

FIG. 3 is front view of the welder; and,

FIG. 4 is a top view of the welder.

The broken lines in FIGS. 1-4 are for illustrative purposes only and form no part of the claimed design. More specifically, dashed broken lines define unclaimed features. Dot-dash broken lines, drawn with heavier weight than the dashed broken lines, define boundaries of the claimed design. 

The ornamental design for a welder, as shown and described. 